I've gotten several such calls in the past week, also. I have also applied for many online jobs, including with the federal government, so any of the above explanations could be correct.
Third or fourth call from this number. Answered call for the first time and listened to a robocall message about a program to provide seniors with free life saving devices to make a call for help in an emergency. The call finished with a something to the effect of "Press 1 to find out more about this life saving device or press 5 to be removed from the list."